So, one of my wife's friends asked if I would be interested in a free collection of non-working 8 track players, along with several boxes of 8 tracks. I don't have a place to put them, I don't have any speakers or an amp to plug them into, and I don't really have time for another project.
So of course I said yes. There's four non working 8 track players, and four boxes of tapes for them. Some of the tapes are definite classics, although I haven't really gone through them all yet.
So the first order of business was to get a set of speakers to plug into them. As I really don't want to spend any more on this project than necessary, there was one clear option...
Pair of Kenwoods and a cable for $12. They're a little newer looking than the 8 track players, but the closest ones they had to period correct. So I tried hooking all of them up directly and plugging in a tape. Didn't want to risk one of the potentially valuable tapes, but some were recordings and copies.
Final tally: Two do absolutely nothing. One has a working radio that puts out sound but the tape doesn't play. And one does something when you put a tape in, but it wasn't anything desirable, just a bunch of screeching sounds (and nothing through the speakers).
I'm going to take that personally. We'll see what's inside soon...
About 2 decades ago I was presented with the same offer. I cutrently have several 8 track players, a couple of large moving boxes full of tapes, and a few auto 8 track players scattered around now, none of which have made a sound in probably a decade.
It was neat tech, for it's time, but it's maddeningly touchy, and the tapes break with alarming regularity. I'd donate mine to a museum in a hot minute if I could find one that wanted them.
I'll figure out what I will use them for once I get these apart and assess how badly damaged they are. It's entirely possible one of these may end up playing a Spotify stream instead of 8-tracks.
You'll find that the tapes with foam pressure pads will have succumbed to foam rot. Can be rebuilt with a bit of effort. There are kits. In terms of the players, it's usually a drive belt, grease on the track selection mechanism (the stepped cam & solenoid that moves the head up and down) hardens up. Oh, also dirty record play switches on players that have that feature. Good luck!
Also, check out this documentary about eccentrics using 8 tracks in the 90s. So wrong they're right
Approach all positive claims about 8 track sound quality with deep skepticism
In automotive terms, 8 track tapes are basically the Fiat X 1/9 of the audio world. They're not particularly reliable, and even when they're working perfectly they don't work particularly well. No one really wants them, they're cheap, and most people will look at you like you have 3 belly buttons when you start talking about them.
flat4_5spd said:
Also, check out this documentary about eccentrics using 8 tracks in the 90s. So wrong they're right
Approach all positive claims about 8 track sound quality with deep skepticism
The sound quality issue is basic physics. An 8 track tape is 1/4" wide; considering each "side" has two tracks, for stereo, that's 1/32" of tape width per channel. So it'll sound, at best, as good as a cheap cassette, except that instead of only two possible head positions, there are 4, and it's relying on a mechanical mechanism to cycle through them and stay aligned.
The tapes usually break right at the end, where the continuous tape is spliced together. It's possible to re-splice, and most times the little metal strip that signals to the machine to advance to the next track will be broken off. I used to fashion replacements using aluminum foil. Splicing can be done with Scotch tape. A razor blade is best for cutting tape and foil. It also works well for slicing the tape label so the tape cartridge housing can be opened up.
I'm first taking each apart to see what issues I can find. I don't have an isolation transformer, so I will not be testing them under power with the enclosure open. First up is this little Centrex.
In hindsight, I probably could have taken it apart without removing that screw. But there weren't any adverse consequences either.
Here's what is behind the panel.
Removing the screws underneath allows everything to slide out the front on a metal chassis.
I think the playback head is supposed to be attached to something, isn't it?
This microswitch switches the 110 volt AC power when you insert a tape. Or it did. Now it does nothing except smell burnt.
Next up is a larger Centrex. This one has some groovy V-U meters on the front. It's the one that powered up but made weird screeching sounds.
Sigh. Haven't we been over this already?
Here's what is inside.
This one uses a more sophisticated way to trigger the microswitch instead of a flat blade just being pushed aside. Better protection for the switch; that may be why it survived.
So what went wrong? This may be a clue...
That brown stuff at the base of the capacitors could be glue to hold them in place. But it probably is supposed to be inside the capacitors. On to the next teardown!
The next one is an ICP-branded player / recorder. Thankfully, I found no evidence that it contains or ever contained any clowns.
This one uses a much cruder microswitch.
Unlike the Centrex players, this microswitch appears to operate a low voltage connection; the mains voltage only runs into the transformer. And the microswitch works, but the unit still doesn't power up and there is no visible electrical damage. This one is probably the worst candidate for repair: I don't see how I'd be able to troubleshoot without powering it up, and I'm not going to plug it into mains voltage with the cover off with the equipment I have.
Last up is the Realistic branded radio / 8 track. I had high hopes for this one since the radio portion is working. Similarities in the construction and parts suggest this was made by the same contract manufacturer that made the first Centrex unit I looked at.
But one whiff of the scent in the case, that burnt polyester smell if you've worked with electronics, and I suspected it would not be an easy one to fix either.
Like the ICP unit, it used a fairly simple microswitch that switches low voltage. And testing with a multimeter confirmed it's in good working order.
Looks like the exact same playback head assembly as the small Centrex - except put together correctly.
Looks like more capacitors that aren't capaciting. In the second picture, you can see a dark brown smudge just peeking out from the capacitor under the wires.
So, does it make sense to fix any of these? The small Centrex looks like re-installing the playback head and replacing the microswitch might get it working. The others all look like they'd need board level repairs.
Why not just jumper the microswitch in the Centrex and see if the motor runs? I suspect that the plastic bracket that holds the head is cracked. I have a similar player and the combination of the constant tension from the screw that clamps down on the head and old plastic leads to failure.
I know it's unpleasant to be stung by 110vac, but with basic common sense and care there's not too much risk of fiddling around inside these things with the covers off and plugged in. When I was in college my dorm stereo comprised a motley assortment of cast-off equipment, most of which was under perpetual repair. I rarely had covers on anything even when I was listening to music, since chances were good something would need to be fixed soon.
One time my CD player got an attitude and Frisbee'd a disc across the room at my roommate. I don't know what RPM they spin at, but it was fast enough to nick him in the neck.
flat4_5spd said:
Why not just jumper the microswitch in the Centrex and see if the motor runs? I suspect that the plastic bracket that holds the head is cracked. I have a similar player and the combination of the constant tension from the screw that clamps down on the head and old plastic leads to failure.
That's more or less the plan. Although I might be able to transplant the other high voltage micro switch instead of a jumper.
Powering the unit up with the cover off and on 110 volts isn't something I have ruled out completely. I've worked on a few sketchier bits of electronics, including having a circuit board that was carrying 220 volts let the smoke out while I was adjusting a trim pot.
That Radio Shack stereo is the same model as my first, real stereo set. I finally tossed it about 10 years ago. It worked fine. I just didn't need multiple stereos in the house. I hope you can get them all working with very little effort.
OK, jumpering the microswitch got the motor turning. I don't have a replacement, and this is a pretty much no budget fix... can I repair the switch?
Yep, got it apart and cleaned the contacts with a Magic Eraser, and the switch is in business! Unfortunately, the head won't stay aligned. Looks like this plastic has been broken and glued together a few times.
I may see if the plastic mount out of the radio / 8 track unit fits and is in any better shape.
